The present invention refers to a system for pneumatically automating mobile sliding and/or rolling screens, particularly for sun screens, curtains, mosquito-nets, thermal screens, panels, sliding doors and windows, windows both for civil and for industrial buildings.
The need for automating rolling sun screens and/or mosquito nets is particularly felt under different situations, in particular when:                it is difficult to reach the screen, for example like when a window is very high or is arranged in a staircase room;        the screen is part of an extended group of similar apparata, that must be able to be controlled in a centralised way, for example in case of an extended darkening system in a building with offices;        the screen must be frequently driven, maybe by an operator with engaged hands, such as, for example, in the kitchen entry of a restaurant, a shop entry, the access for exchanging materials to a cash counter or a motorway fare stations (in order to limit the cooling of the environment in which the operator resides);        the screen must be able to be quickly driven but with an external control, in order to avoid unwanted accesses, such as, for example, in case of access to a working area with moderate risks even only for the operator's hands, like an area with projection of liquids-chips in an industrial process, an access area to a tunnel-type dish-washing machine for restaurants (replacing the plastic bands, that come in contact with kitchenware and surely are not sterile);        the opening to be protected is a door; in this case the technically more reliable arrangement is, as known, a vertical rolling screen; however, this arrangement is uncomfortable for the drivability, compelling the user to bend down for closing it and, if the product has not a braked opening, also for its opening. The currently adopted arrangement is an horizontally-opening screen, which can be easily driven, but that however has the inconvenience of having a housing outline of the screen on the ground, such outline being an obstacle to a passage even if of reduced sizes;        it is desired to adjust the brightness inside a room quickly, repeatedly and silently in order not to cause any disturbance, checking the sun screen position by coupling the automation system to a brightness sensor and to a position sensor;        it is desired to realise an effectively operating energy saving system. In order to realise such effect, both in case of heating and, more so in case of air conditioning, it is necessary to be able to position the screen outside. In case of heating, in fact, it is necessary to create a tepid air chamber between the window containing the heated room and the outside, in order to expose to the external temperature a surface with intermediate temperature between the internal temperature and the temperature (in case of a typical winter evening equal to 3° K) of the bottom radiation. Since the heat propagation by radiance is proportional to the square of the temperature difference between the two heat sources, it is immediately evident that breaking the heat propagation with an intermediate temperature is extremely good (10*10=100+10*10=100, is much lower than 20*20=400!). With an internal screen, instead, the screen temperature remains much nearer to the room temperature, greatly reducing the effect. In case of conditioning, instead, the advantage of having an external screen is that, one the visible radiation has managed to enter the room, it is converted into an infrared radiation on internal curtains with the effect that it is not able any more to go out of the glass that has now become opaque. This effect can be reduced by adopting an aluminium-coated screen, but not in a final way. Therefore, in order to adopt an interesting saving strategy, it is necessary to be able to use and external screen that is automatic, quick, silent and, above all, reliable, given that, due to its external location, every type of maintenance would be extremely uncomfortable in the majority of times. Moreover, being able to couple the automation system with a presence sensor, it would be possible to keep the darkening screens closed when there is no human activity in the room, and open them as soon as the access door is opened. Also for this application, silent, reliable and discrete automation systems for darkening screens are preferable;        the screen, in particular when it is a mosquito net, is placed external to the window or door frame. In this case, it would be desirable that, when the frame is closed, the mosquito net is opened, in order to limit its aesthetically unpleasant view. However, when the frame is opened, it is important to close the mosquito net in order to avoid, especially during summer nights, the entry of insects. By manually driving the screen, however, it is necessary to first open the window and then to lower the screen, or vice versa, to first open the screen and then close the window, thereby leaving a time interval in which both mosquito net and frame are open, such interval being more than enough to allow mosquitoes to enter. Due to an efficient mosquito net automation system, it would however be possible to avoid this, since the screen could be easily driven from the inside. Moreover, if the automation system could guarantee a high mosquito net actuation quickness and a high level of intrinsic safety, it would be possible to drive the mosquito net directly by actuating the window, guaranteeing its perfect closure before the window is actually opened, making its use still easier and more efficient.        
In the current art, a rolling screen currently consists in a box placed in an upper position with respect to the opening to be protected, containing a generally metal tube, on which the textile screen is wound.
Laterally, on the opening sides, two generally metal guides are located, which allow the screen dragged by its handle bar to correctly descend and to remain in its correct position.
Further object of the guides is that, through suitable gaskets, or even simply a labyrinth path, light does not laterally enter in case of a sun screen and insect, in case of a mosquito net, are not able to pass by the net sides. In the winding tube, a torsional spring is further contained, with the purpose of balancing or also rewinding the textile cloth.
The problem of automating darkening screens and mosquito nets is currently solved by electrically motoring them. In particular in standard systems, the motor is contained in the above tube, with evident dimensional limits, and the cloth descends when subjected to the only tension, typically a scarce one, induced by the handle bar weight. This configuration is subjected to several problems, and in any case to high installation costs (minimum 100C- only for the motor of an automation system for a window rolling screen). In particular, known automation systems through electric motoring have the following intrinsic and assembling disadvantages that are strongly negative:                they have scarce reliability, since the necessary power density (W/cm3) is very high, not because a high power is required, but because the space inside the tube is very small: this compels, for rather heavy systems, to adopt exaggeratedly big tubes with the disadvantage of having big final overall sizes, anyway resulting in being able as a maximum to perform few consecutive maneuvers (as a limit 2 or 3) before the motor enters in thermal protection or is damaged beyond repair;        they are noisy: since the motor has to be made with small sizes, it is necessary to rotate it at very high speeds and then equip it with a reducer, typically of the epicyclic type, that, in order to remain inexpensive, is always made in a version with straight teeth, such characteristic making it extremely noisy; anyway, even by equipping the motor with a high-range speed reducer, the silent operation is well far from being deemed tolerable in a civil application (suffice it to think that the typical manoeuvre time of a screen is a night, probably in a sleeping room);        they are costly: always due to the high necessary power density, they are costly technologic products. Typically, small-sized motors are direct current motors with permanent magnets; if it is not possible to do without them, asynchronous single-phase motors are adopted, adding the further disadvantage (in addition to the obvious one of high sizes) of not being able to adjust the speed unless very costly inverters, of a typical industrial application, are used;        they have a limited life, which makes them absolutely unsuitable to operate in a real automatic system, unless they are seldom used for driving unreachable screens, or for reasons of appearance in very costly buildings, at the expense, in addition to installation costs, of frequent replacements;        they are slow due to the necessary high reduction ratio to allow the limited power to move the screen;        they need an accurate limit switches adjustment since a wrong adjustment would imply, in the best case, an incomplete screen opening/closing or a screen de-tensioning in its close deposition and, in the worst case, to a ratio-motor breakage due to the occurrence of the maximum-opening mechanical lock; moreover, at any time the lack of intervention of one of the limit stops occurred, an operating logic reversal would occur (namely the screen would be completely unwound to be then re-wound on the opposite part, generating the switching of the “open” limit switch with the “closed” one) with sure motor damages and an almost certain ratio-motor breakage;        being equipped with an electric drive, in order to be able to be assembled on the outside (typical of a curtain, for example), they need a protection at least equal to IP55, absolutely out of discussion for an object for domestic use: from this, it is deduced that, apart from rare cases, installations performed outside (typically in “bricolage” works) are dangerous (for 220-110V models), or at least amenable to a short life;        they are not adapted to move horizontal screens (typically roof windows), use in which they would find an ideal application, since it is this type of screen that is often reachable with difficulty. Such inadequacy results from the cloth tensioning that is only given by the weight of the handle bar that ends the cloth that, in case of a vertical movement, drags downwards the screen in order to allow its closure: instead, in case of an horizontal movement, the handle bar traction action would obviously have no effect and the screen would not be able to be closed, unless the screen has a sufficient intrinsic stiffness. In order to try and search to realise this type of applications, typically a second spring-loaded winding tube is placed on the screen base, that is connected with two tie-rods to the handle bar that, at that time, is in an intermediate position between two winding systems. The contrast between these two systems creates the necessary tension to support the cloth, while one of the two tubes, being further motored, provides the automation. All these additions further complicate the screen, making it still more costly, difficult to install and even more subjected to malfunctions.        
There are automation systems that can guarantee a quick screen movement, but these are, such as for example in case of a linear axis driven by brushless motors, products with a clear industrial origin, characterised by high installation costs, and therefore scarcely complying with the need of an automation system that is available on a large scale.
Moreover, in all anyway known cases, being the screen left fall from its winding roll without other tensioning apart from its own weight and its own handle bar, the screen itself remains scarcely tensioned and tends to easily go out of its own guides, particularly in case of wind. Moreover, in existing systems, the handle bar freely slides in the guides, compensating possible window and door frame distortions only through a high clearance inside the guides themselves, consequently generating a scarce screen movement quality.
In all cases, anyway, no existing automation system guarantees enough quickness, reliability, inexpensiveness and operating safety to be able to solve one of the previously-described cases to be satisfied.